Seiichi (written: , , , , , , , or ) is a masculine Japanese given name. Notable people with the name include:
, Japanese karateka , Japanese cult member , Japanese politician , Japanese photographer , Japanese philosopher , Japanese art director , Japanese karateka , Japanese video game designer , Imperial Japanese Navy admiral , Japanese academic, historian and writer , Japanese golfer , Japanese politician , Japanese general , Japanese footballer , Japanese inventor , Japanese writer , Japanese photographer , Japanese poet and painter , Japanese footballer , Japanese politician , Japanese sport wrestler , Japanese politician , Japanese footballer , Japanese footballer , Japanese baseball player and soldier , Japanese aikidoka , Japanese philologist , Japanese figure skater , Japanese politician , Japanese handball player , Japanese photographer , Japanese actor , American musician , Japanese educator , Japanese scientist , Japanese baseball player , Japanese musician